The present invention relates primarily to flashlights, and in particular, to miniature hand-held flashlights.
Although miniature flashlights have long been known in the art, it is only been recently, with the development of miniature flashlight lamp bulbs having superior light-emitting characteristics and with improvements in the reflective quality of in flashlight reflectors, that there has developed a genus of high quality miniature flashlights.
U.S. Pat. No. 4,577,263 issued to Maglica discloses one member of this genus. Maglica discloses a high quality, hermetically-sealed miniature flashlight having a rotating head assembly which is used to vary the relative positions of the bulb and the reflector in order to adjust the flashlight beam from broad and diffuse to narrow and concentrated. By continuing to rotate the head assembly so that it is translated towards the tail cap of the flashlight, the circuit between the bulb and the batteries is opened and the flashlight is shut off.
Due to their compact size and their superior light emitting characteristics, these high quality miniature flashlights are particularly useful in emergencies. In these situations, however, it is often the case that only one hand can be spared for operating the flashlight. Unfortunately, it is somewhat cumbersome to actuate the flashlight by rotating the head assembly with one hand. Furthermore, when the flashlight needs to be used as a flashing signal light, the rotating head assembly switch is inconvenient, even when two hands are used to operate the switch.
During a crisis, it is particularly critical that the integrity of the electrical contacts forming the flashlight""s electrical circuit be maintained. Unfortunately, it is in precisely these circumstances that the flashlight is most likely to be dropped and damaged. If the flashlight is dropped, the disproportionately large percentage of the flashlight""s mass located in the head assembly will give the flashlight a tendency to strike the ground head assembly first. This type of a fall will cause the flashlight""s batteries to be driven against the forward wall of the battery retainer, thereby causing a disproportionately large percentage of the impact to be borne by the raised nipple of the positive terminal of the battery which rests against the front wall of the retainer. As a result of this impact force, the nipple may be crushed or dented; thereby, in view of the very small contact area of these miniature batteries, potentially interrupting the flashlight""s electrical circuit.
Therefore, there is needed an improved miniature flashlight which overcomes the drawbacks of prior miniature flashlight designs, while retaining the waterproof and high quality light emitting features which have led to the widespread use of these flashlights.
The invention comprises an improved waterproof flashlight wherein the flashlight is activated by means of a switch located in the flashlight""s end cap.
The flashlight includes an elongate battery retainer, a bi-pin lamp bulb holder, a bulb-battery contact adapted to electrically connect one pin of a bi-pan bulb held by the lamp holder to a terminal of a dry-cell battery in the batter retainer, a head assembly which includes a lens through which light from a bulb held by the lamp holder can be emitted, an end cap opposite the head assembly from the battery retainer, and a switch mechanism in the end cap.
The flashlight also includes means for creating a fluid-tight seal between the head assembly and means for creating a fluid-tight seal between the battery retainer, and the battery retainer and the end cap.
The switch mechanism provides the means by which the flashlight""s electrical circuit can be opened and closed. The switch mechanism includes a nonconductive contact housing which defines a cavity. The switch""s battery-cavity contact is adapted to electrically connect the cavity to a terminal of a battery within the battery retainer having a charge opposite to the terminal electrically connected to the bulb-battery contact of the bi-pin bulb. The switch""s cavity-end cap contact is adapted to electrically connect the cavity to the other pin of a bi-pin lamp bulb retained by the lamp holder. An electrically conductive shorting member is adapted to be movable within the cavity of the contact housing so as to selectively electrically connect and disconnect the battery-cavity contact and the cavity-end cap contact to open and close the flashlight""s electrical circuit.
The switch is operated by means of a plunger/button which is separated from the shorting member by means of a fluid-tight diaphragm. The switch mechanism""s plunger/button is adapted to force the fluid-tight diaphragm against the shortning member and thereby to move the shorting member within the housing cavity to open or close the flashlight""s electrical circuit.
Another feature of the present invention is a means of protecting the raised positive terminals of dry cell batteries in flashlights by means of orienting the positive terminals away from the flashlight""s head assembly and by providing a recess in the contact housing having a depth slightly less than the height of the battery""s positive terminal and a width slightly greater than the width of the battery""s positive terminal so the positive terminal is retained in the recess and is thereby protected from damage by said housing.